GB2128994A

GB2128994A - Polyester compound

Info

Publication number: GB2128994A
Application number: GB08326814A
Authority: GB
Inventors: Kiyoshi Okitsu; Akira Yamamoto
Original assignee: Daicel Chemical Industries Ltd
Current assignee: Daicel Corp
Priority date: 1982-10-08
Filing date: 1983-10-07
Publication date: 1984-05-10
Also published as: US4454313A; GB8326814D0; DE3336226A1; JPS5967248A; GB2128994B; DE3336226C2

Description

1

SPECIFICATION

Polyester compound GB 2 128 994 A 1 The present invention relates to a new polyester compound.

Plasticized vinyl chloride resin products have been used widely for various purposes. Recently, the regulation on the safety of electric wire coatings and automobile parts has been tightened and, therefore, improvement in heat resistance of them has been eagerly demanded. Further, heat resistance is required also of additives used for lowering the crystallization temperature of polyethylene terephthalate resins, since the blending temperature of them is high.

Known plasticisers include dialkyl phthalates prepared from monohydric alcohols having 9 to 13 carbon atoms, such as dinonyl phthalate, diisodecyl phthalate and ditridecyl phthalate, having a heat resistance higher than that of di-2-ethylhexyl phthalate (DOP) which is a typical plasticizer. In addition, known plasticisers also include alkyl esters of aromatic tribasic and tetrabasic carboxylic acids prepared from monohydric alcohols having 6 to 10 carbon atoms, such as trihexyl trimellitate, tri-2-ethylhexyl trimellitate, triisodecyl trimellitate and tetra -2-ethyl hexyl pyromellitate.

However, the above-mentioned plasticizers have defects thatthe proportion of the polar groups in the molecule is reduced as the carbon number of the alcohol is increased, wherebythe compatibility with a vinyl chloride resin is reduced and processability such as the gelling property becomes insufficient. Another defect is that the plasticizer bleeds on the resin surface.

As other plasticizers, there may be mentioned a polyester having a molecular weight of 500 to 10,000 prepared by dehydration condensation of a dibasic carboxylic acid such as adipic acid with a glycol such as propylene glycol or 1,3-butanediol and a polyester obtained by modifying a terminal group of the above-mentioned polyester with a fatty acid or an alcohol. However, the processability of the polyester deteriorates as its molecular weight is increased, though its heat resistance is improved. When the polyester 25 is used in combination with a lead stabilizer mainly used for stabilizing the vinyl chloride resin used as an electric wire coating, the resin cannot exhitbit a sufficient insulating property and the polyester bleeds easily under a high humidity condition.

As compared with a polybutylene terephthalate resin, a polyethylene terephthalate resin has an inferior mouldability, since the latter has a high crystallization temperature. For using the polyethylene terephthalate 30 resin more widely, the lowering of its crystallization temperature by the use of an additive is now investigated.

As an additive used for this purpose, there has been proposed a polyester having a molecular weight of 500 to 10,000 obtained by dehydration condensation of a di basic carboxyl ic acid such as adipic acid with a glycol such as propylene glycol or 1,3-butanediol or a polyester obtained by modifying the terminal group of 35 the above-mentioned polyester with a fatty acid or an alcohol. However, since these polyesters must be kneaded with the polyethylene terephthalate at a high temperature, they are thermally decomposed, resulting in deterioration of physical properties such as tensile strength.

After intensive investigations made for the purpose of solving the abovementioned problems, the inventors have found that a caprolactone-modified polyester can be used as a plasticizer for a vinyl chloride 40 resin or a modifying agent for a polyethylene terephthalate resin, since it has excellent compatibility, heat resistance and workability; said caprolactone-modified polyester being obtained by a ring-opening polymerization reaction of (o-caprolactone with a polyester polyol, prepared from an aliphatic dihydroxyl compound and an aromatic or aliphatic polybasic carboxylic acid, to obtain a polymer having an average molecular weight of 700 to 3,000 followed by termination of the same with an aromatic monocarboxylic acid, 45 The present invention has been completed on the basis of this finding.

The present invention provides a polyester compound represented by the general formula:

50) (C)h (D) 1 50 [(D p [(B") (C), (D91q (A) //. U ) (c)m (D Yr ///) (C)n (D ///),5 55 wherein: 60 (A) is a residue of an aromatic carboxylic acid having 1 to 4 carboxyl groups and 1 or 2 aromatic rings or a 60 residue of an aliphatic carboxylic acid having 1 to 4 carboxyl groups and 4to 37 carbon atoms, (B), (B'), (B") and (B) may be the same or different and each is a residue of a saturated, straight-chain or branched aliphatic diol having 2 to 6 carbon atoms, (C) is a residue of w-hydroxycaproic acid and h, /, m and n are numbers larger than 0, and (D), (D'), (D") and (D)maybe the same or different and each is a residue of an aromatic monocarboxylic acid having 1 or 2 65 r.

2 GB 2 128 994 A 2 aromatic rings, the respective residues being bonded with each other through an ester bond and selected so as to give the average molecular weight of 700 to 3,000 by properly adjusting the values of h, /, m and n, and p, q, r and s are each zero or one, the total of them being from one to four.

The (o-hydroxycaproic acid residue is derived preferably from Ecaprolactone. It is also possible, however, to derive the w-hydroxycaproic acid residue from the a)-hydroxycaproic acid perse in the course of the 5 preparation of the compound represented by the above general formula.

The present invention provides also a process for producing a polyester compound represented by the general formula:

t(B) (D) 1 (C)h p 4.)'q X)"-, (C), (D1 :Z--, 11 ) (OM (D 11)1r (11 (D111)s ú3) (C)n wherein 20 (A) is a residue of an aromatic carboxylic acid having 1 to 4 carboxyl groups and 1 or 2 aromatic rings or a 20 residue of an aliphaticcarboxylic acid having 1 to 4carboxyl groups and 4to 37 carbon atoms, (B), (131, (B9 and (B) may be the same or different and each is a residue of a saturated, straight-chain or branched aliphatic diol having 2 to 6 carbon atoms, (C) is a residue of w-hydroxycaproic acid and h,/, m and n are numbers larger than 0, and (D), (13% (D") and (D') maybe the same or different and each is a residue of an aromatic monocarboxylic acid having 1 or 2 25 aromatic rings, the respective residues being bonded with each other through an ester bond and selected so as to give the average molecular weight to 700 to 3,000 by properly adjusting the values of h, 1, m and n, characterized by reacting:

(a) 10to 90 molar% of E-caprolactone orw-hydroxycaproic acid, (b) a hydroxyl component comprising one or more saturated, straight-chain or branched aliphatic diol 30 having 2 to 6 carbon atoms, (c) an aromatic polybasic carboxylic acid component having 1 or 2 aromatic rings or an aliphatic polybasic carboxylic acid component having 4to 37 carbon atoms and (d) an aromatic monocarboxylic acid having 1 or 2 aromatic rings, in such a manner that the hydroxyl component is used in a stoichiometric amount or up to 20% excess 35 based on the acid components. The total amount of the components (b), (c) and (d) is 90 to 10 molar percent based on the amount of the caprolactone component.

The symbol (A) is the above general formula represents a residue of an aromatic carboxylic acid having 1 to 4 carboxyl groups and 1 or 2 aromatic rings or a residue of an aliphatic carboxylic acid having 1 to 4 carboxyl groups and 4 to 37 carbon atoms. As the aromatic carboxylic acid, there may be mentioned a monobasic carboxylic acid such as benzoic acid or toluic acid; a dibasic carboxylic acid such as phthalic acid, isophthalic acid, terephthalic acid, methylphthalic acid, naphthalene- dicarboxylic acid, tetrachlorophthalic acid ortetrabromophthalic acid; a tribasic carboxylic acid such as trimellitic acid ortrimesic acid; a tetrabasic carboxylic acid such as pyromellitic acid or benzophenonetetracarboxylic acid; or an anhydride or ester of 45 the above-mentioned monobasic to tetrabasic carboxylic acids. As the aliphatic carboxylic acid, there may 45 be mentioned a monobasic carboxylic acid such as lauric acid, stearic acid, cyclohexenecarboxylic acid or methyl cycl ohexe neca rboxyl ic acid; a dibasic carboxylic acid such as adipic acid, azelaic acid, nadic acid, chlorendic acid, tetrahydrophthalic acid, hexahydrophthalic acid, 3methyltetrahydrophthalic acid or 3-methyihexahydrophthalic acid; a tribasic carboxylic acid such as 1,3-dimethy]-1,2,3- cyclo hexantrica rboxyl ic acid or 1 -ca rboxy-4-methylcycl ohexyisucci n ic acid; a tetra basic ca rboxyl ic acid such 50 as methylcyclohexenetetracarboxylic acid; or an anhydride or ester of the above-mentioned monobasicto tetrabasic carboxylic acids. From the viewpoint of physical properties, economic advantage and availability of the starting material, it is particularly preferred to use phthalic anhydride, isophthalic acid, terephthaiic acid or trimellitic anhydride.

The symbols (B), (13% (131 and (B in the above general formula represent a residue of a saturated 55 straight-chain or branched aliphatic diol having 2 to 6 carbon atoms and they may bethe same or different from one another. As the diol compound, there may be mentioned, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3- butanediol, neopentyl glycol or 1,6 hexanediol. Among these compounds, ethylene glycol, diethylene glycol, 1, 4-butanediol or neopentyl glycol is used particularly preferably from the viewpoint of physical properties, economic advantage and reaction 60 operations.

The symbol (C) in the above general formula represents an whydroxycaproic acid residue. From the viewpoint of the economic advantage and reaction operations, it is preferred to use F--caprolactone.

The symbols h, 1, m and n are values largerthan 0. The sum total of h, 1, m and n is 0.2 to 30, preferably 0.5 to 20.

1 1 3 GB 2 128 994 A 3 The symbols (D), (D'), (D"), and (D) in the above general formula represent an aromatic monocarboxylic acid residue having 1 or 2 aromatic rings and they may be the same or different from one another. From the viewpoint of physical properties, economic advantage and availability of the starting material. it is preferred to use benzoic acid or toluic acid as the aromatic monocarboxylic acid.

The present invention provides also a process for producing a polyester compound represented by the 5 above general formula which comprises reacting the following components (a) to (d):

a) 10to 90 molar% of F--caprolactone orw-hydroxy caproic acid, b) a hydroxyl component comprising one or more saturated, straight-chain or branched aliphatic diol having 2 to 6 carbon atoms, c) an aromatic polybasic carboxylic acid component having 1 or 2 aromatic rings or an aliphatic 10 polybasic carboxylic acid component having 4 to 37 carbon atoms and d) an aromatic monocarboxyiic acid having 1 or 2 aromatic rings, in such a manner thatthe hydroxyl component is used in a stoichlometric amount or up to 20% excess based on the acid components and the amount of the lactone and the ratio of the remaining reactants are controlled so that the resulting product will have an average molecular weight of 700 to 3,000.

The polyester represented by the above general formula may be produced by an ordinary process wherein a dihydroxyl compound is reacted with a dicarboxylic acid. In a convenient process, a mixture of the reactants is heated to 100 to 2500C under such a condition that water formed by the condensation reaction is removed by introducing an inert gas into the heated reaction mixture or by carrying out the reaction in the presence of an adequate inert solvent which forms an azeotropic mixture with the formed water, such as 20 toluene or xylene. Preferably, the reaction is continued until the content of the terminal carboxylic group in the resulting polyester corresponds to an acid value of less than 10 mg, preferably less than 1 mg of potassium hydroxide per gram of the polyester.

If necessary, a catalyst generally used in the production of polyesters may be added to the reaction mixture. The catalyst includes a strong acid such as sulfuric acid, p- toluenesulfonic acid or phosphoric acid; 25 a Lewis acid such as stannic acid; zinc chloride; aluminium chloride, a metal salt and a metal alkoxide or a derivative thereof such as tetrabutyl titanate zinc adipate, antimony oxide or an organotin compound. The amount of the catalyst used is in the range of 0.0001 to 2 wt.% based on the whole reaction mixture.

When the polyester compound of the present invention is used as a plasticizer for a vinyl chloride resin, an extraction resistance, migration resistance, heat resistance and processability superior to those of a 30 conventional non-migrating plasticizer can be obtained and main defects of this type of the plasticizers can be overcome.

The polyester compound of the present invention may be incorporated in a thermoplastic polymer such as vinyl chloride resin or its copolymer according to a conventional process. If necessary, the thermoplastic composition may contain other additives such as a heat stabilizer, light stabilizer, antioxidant, filler, pigment, 35 lubricant and processing aid as well as other plasticizers.

As the heat stabilizer and light stabilizer, the following substances may be mentioned:

1) an inorganic or organic acid salt containing any metal having an effect of stabilizing the vinyl chloride resin; the metal including, for example, aluminium, barium, bismuth, calcium, cadmium, potassium, lithium, magnesium, sodium, lead, antimony, tin, strontium and zinc, perse or its salt. The salt maybe either a single 40 salt or a complex salt.

The inorganic salt is, for example, basic lead carbonate or tribasic lead sulfate. The organic acid used may be as follows:

a) a straight-chain or branched, saturated or unsaturated, aliphatic carboxylic acid which may have a hydroxyl substituent or oxygen atom in the epoxy group, such as zinc 2- ethylhexanoate, barium laurate or 45 stannous octanoate, b) an aromatic mono- or dicarboxylic acid having any type of substituent in its aromatic group and any alkyl/ary! configuration, such as cadmium p-t-butylbenzoate, calcium benzoate or zinc salicylate, c) a phenol capable of behaving as an acidic substance to form astable compound with a metal irrespective of the presence or absence of a suitable solvent, such as barium nonylphenate, 2) an organometallic compound containing a metal selected from aluminium, barium, bismuth, calcium, cadmium, potassium, lithium, magnesium, sodium, lead, antimony, zinc, tin and strontium, such as a dialkyltin mercaptide or a dialkyltin carboxylate, and 3) any sort of organic compounds capable of preventing deterioration of the vinyl chloride resin.

The organic compounds include, for example, ot-phenylindole or an aminocrotonic acid ester. These 55 compounds may be used either alone or in the form of a mixture or a solution in a suitable solvent which is not limited to a stabilizer. They may be used in the form of a combination of calcium carboxylate/zinc barium phenate/cadmium salt of a branched fatty acid, or barium carboxylate/cadmiumIzinc carboxylate.

There may be used a substance which improves the effects of the abovementioned stabilizer when it is used in combination with the stabilizer, though it per se exhibits no stabilizing effect when it is used alone. 60 This substance is called---aco-stabilizer" and includes the following compounds:

a) an epoxidized oil such as epoxidized soybean oil, oran ester such as epoxidized octyl oleate, b) a trialkyl, triaryl or alkylaryl phosphite such as tri phenyl phosphite, tris(nonyl phenyl) phosphite or diphenylisodecyl phosphite.

c) a partial ester of pentaerythritol, neopentyl glycol, sorbitol or glycerol, or 4 GB 2 128 994 A 4 d) a phenol compound such as 2,6-di-t-butyl-4-methyl phenol or 2,2-(4- hydroxyphenyl)propane.

These co-stabilizers may be used either alone or in the form of a mixture of them. They may be combined with the main stabilizer in any ratio and in any desired combination.

The co-stabilizer may be used alone in its natural form or in the form of a mixture with the stabilizer. The co-stabilizer may also be used in the form of a solution of the same alone or that of a mixture with the stabilizer in a suitable solvent which is not limited to the stabilizerfor the vinyl chloride resin.

The plasticizer may be used in the form of a mixture with a lubricant such as a polyethylene wax, ester wax, stearic acid, calcium stearate or lead stearate, or a filler such as pulverized or precipitated calcium carbonate or china clay.

The plasticizer may be used together with a substance which absorbs ultraviolet rays to increase the 10 stability of the vinyl chloride resin against light, such as benzophenone or benzotriazole.

The above-mentioned plasticizer may be used also in the form of a mixture with the following, known plasticizer:

a) a flame-retardant such astriaryl phosphate or an alkyldiaryl phosphate, b) a phthalate ester, c) a plasticizer such as an ad ipate, sebacate or azel ate, d) a poly(1,3-butylene glycol adipate) terminated with an alcohol having 8 carbon atoms ora conventional polyester plasticizer such as another typical polymer of this type, e) an aryl ester of an alkane sulfonic acid, or f) an extender containing a halogenated paraffin or an aromatic hydrocarbon.

When the polyester of the present invention is used as a modifying agent for a polyethylene terephthalate resin, the crystallization temperature of this resin can be lowered to an extent greater than that attained by using an ordinary polyester modifying agent. Further, the polyester of the present invention exhibits excellent compatibility, heat resistance and processability as a modifying agent for the polyethylene terephthalate resin.

The following examples will further illustrate the present invention, which by no means limitthe scope of the present invention. In the examples, parts are given by weight.

Example 1.

249 parts of terephthalic acid, 374.4 parts of neopentyl glycol, 681 parts of E-caprolactone, 366 parts of 30 benzoic acid and 3.34 parts of a 1 % solution of tetrabutyl titanate in heptane were charged in a 2-1 four-necked flask provided with a thermometer, nitrogen-inlet tube, stirrer and condenser and reacted under introduction of nitrogen at 200 to 220'C for 32 h to obtain 1,550 parts of a lactone polyester having an average molecular weight of 1,000.

Properties of the lactone polyester.' hue (APHA) acid value (mg KOH/g):

OH value (mg KOH/g):

viscosity (cP/25'C):

250 0.01 5.2 9,100 GB 2 128 994 A 5 Example 2

332 parts of terephthalic acid, 499.2 parts of neopentyl glycol, 508 parts Of E-caprolactone, 488 parts of benzoic acid and 3.65 parts of a 1 % solution of tetrabutyl titanate in heptane were charged in the same device as in Example 1 and reacted under introduction of nitrogen at 200 to 220T for 30 h to obtain 1,650 parts of a 5 lactone polyester having an average molecular weight of 800.

Properties of the lactone polyester:

hue (APHA)..

0 0 CH3 0 11 11 1 11 11 X.-C--Cu(-t12 H20--f-C(CH 0--C 25 n CH.

3 Example 1: m + n = 3.98 on average Example 2: m + n = 2.23 on average.

Claims

CLAIMS wherein:

acid value (mg KOH/g):

OH value (mg KOH/g):

viscosity (cP/25T):

0 0.04 6.7 13,000 0 CH, OCH 2CCH 0-X P-C-f-0 (Cl)5 m 1 2 CH3 0 1. A polyester compound represented by the general formula:

[(8) (C)h (D) 1 p Iffl,') (C), W] (A):::. q 1 (c), (D Tr m (C)n (D111)15 (A) is a residue of an aromatic carboxylic acid having 1 to 4 carboxyl groups and 1 or2 aromatic rings or a residue of an aliphatic carboxylic acid having 1 to 4 carboxyl groups and 4 to 37 carbon atoms, (B), (13% (131 and (B) may be the same or different and each is a residue of a saturated, straight-chain or branched aliphatic diol having 2 to 6 carbon atoms, (C) is a residue of w-hydroxycaproic acid and h,/, m and n are numbers larger than 0, ' (D), (D1 (T) and (D) may be the same or different and each is a residue of an aromatic monocarboxylic acid having 1 or 2 aromatic rings, the respective residues being bonded with each other through an ester bond and selected so as to give the average molecular weight of 700 to 3, 000 by adjusting the values of h, 1, m and n, and p, q, r and s are each zero or one, the total of them being from one to four.
2. Acompound as claimed in claim 1, inwhich thesum total of h,l, m and n is 0.2to 30.
3. Acompound as claimed in claim 1, in which thesum total of h,lm and n is 0.5to 20.
4. A compound as claimed in anyone of claims 1 to 3, in which the aromatic carboxylic acid residue A is a residue of phthalic anhydride, isophthalic acid, terephthalic acid ortrimellitic anhydride.
5. A compound as claimed in anyone of claims 1 to 4, in which the diol residue B is a residue of ethylene glycol, diethylene glycol, 1,4-butanediol or neopentyl glycol.
6 GB 2 128 994 A 6 6. A compound as claimed in anyone of claims 1 to 5, in which the aromatic monocarboxylic acid residue D is a residue of benzoic acid or toluic acid.
7. A vinyl chloride resin containing a compound as claimed in anyone of claims 1 to 6.
8. A polyethylene terephthalate resin containing a compound as claimed in anyone of claims 1 to 6.
9. A process for preparing a caprolactone-modified polyester, which comprises reacting 10 to 90 molar 5 percent of epsilon-caprolactone or omega-hydroxycaproic acid with 90 to 10 molar percent of (b) a hydroxyl component comprising one or more saturated, straight-chain or branched aliphatic diols having 2 to 6 carbon atoms, (c) an aromatic polybasic carboxylic acid component having 1 or 2 aromatic rings or an aliphatic polybasic carboxylic acid component having 4 to 37 carbon atoms, and (d) an aromatic monocarboxylic acid having 1 or 2 aromatic rings, said hydroxyl component (b) being used in a stoichiometric amount or up to 20 percent larger amount than the said acid component (C), the obtained product having an average molecularweight of 700 to 3,000.
10. A process as claimed in claim 9, in which the reactants are so chosen that the polyester obtained is as claimed in any one of claims 1 to 6.
11. A compound as claimed in claim 1, and substantially as hereinbefore described with reference to 15 Example 1 or Example 2.
12. A process as claimed in claim 9 and substantially as hereinbefore described with reference to Example 1 or Example 2.

Printed for Her Majesty's Stationery Office, by Croydon Printing Company Limited, Croydon, Surrey, 1984. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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